Supercharged internal-combustion engine



L A S N R O H T H D SUPERCHARGED INTERNAL-COMBUSTION ENGINE 2Sheets-Sheet 1 Filed Dec. 9, 1942 penis E Tlorm 'Uuncan Mag MW 9 Sept.l3, E949. D. H. THORNS ETAL 2,482,040

SUPERCHARGED INTERNAL-COMBUSTION ENGINE Filed Dec. 9, 1942 2Sheets-Sheet 2 ANTI-DETONANT I 96 frwenfbrs Juneau Jammy 5' arm-mm #MM(Elfin-1163s Patented Sept. 13, 1949 2.48%040 SUPERCHARGEDINTERNAL-COMBUSTION ENGINE Denis Heston Thorns an tol, England,assignors Company Limited, B

company Application December 9. 1942, Serial No.

d Duncan Ramsay, Bristo The Bristol Aeroplane ristol, England, a BritishIn Great Britain October 9, 1941 Section 1. Public Law Patent expires 11Claims. 1

690, August 8 1946 October 9. 1961' in or relating to superchargedinternal-combustion engines and is of particular advantage for use inconnection with aircraft engines although not limited thereto. Theinvention, however, will be described with reference to aircraftengines.

At the higher pressures of supercharge which are used in such engines(for example during take-off and all-out level flight) there is atendency to detonation even though additional fuel is passed to theengine to act as an internal cylinder coolant. Supplying ananti-detonant to the engine not only cures this tendency but enablessupercharge pressures to be employed therein which are substantially inexcess of the maximum pressures permissible without the anti-detonant,and enables a reduction of some to of the normal fuel consumption to bemade. Although these advantages may be obtained over the whole range ofoperation of the engine by the continuous supply of an anti-detonant,nevertheless it is normal to restrict the use of the anti-detonant toperiods of short duration when the higher supercharge pressures exist;consequently only a limited supply of anti-detonant is carried in theaircraft. When this limited supply has become exhausted it is essentialto ensure that the conditions of excess supercharge pressure andweakened fuel-mixture referred to cannot be brought about.

It is the object of the present invention to provide a simple apparatusfor effecting a supply of anti-detonant to an internal combustionengine. and for automatically preventing said excess superchargepressure and weakened fuel condition from occurring when theanti-detonant has been exhausted.

The invention is illustrated in the accompanying drawings which arepurely diagrammatic and not to scale: in these drawings Figure 1 is adiagrammatic layout of a part of the induction system of a superchargedinterpal-combustion engine and of an automatic control device forregulating the pressure of supercharge, and

Figure 2 is a diagrammatic lay-out of an apparatus constructed inaccordance with the present invention and associated with thesupercharge control device of Figure 1.

Referring to Figure 1, the supercharger is indicated at H3 and deliversby a pipe I24 to the cylinders of the internalecombustion engine. Athrottle-valve I25 is provided which regulates the admission of theinduction gases to the superpressure of supercharge.

charger and hence the amount of the supercharge pressure. Associatedwith the suction side of the supercharger is a carburetter generallyindicated by the reference numeral I0, the carburetter receiving fuelfrom a pipe I26 having an associated needle valve I21 which is operatedin known manner by a float I28. Air is drawn into an intake I29 by thesupercharger and passes through a venturi I30, thereby creating apressure reduction in the jet pipe I3I. The fuel is therefore drawn fromthe carburetter into the jet pipe and mixing with the air in theventuri. passes towards the inlet of the supercharger.

With a view to varying the datum setting of the fuel-air mixture, avalve I54 is provided, the valve having a calibrated orifice I32 whichis capable of placing the jet pipe I3I in communication with theatmosphere. When this is done by adjustment of arm III the suction headof the venturi is diminished and as a consequence less fuel is drawnfrom the carburetter into the pipe I3I. The fuel-air mixture istherefore weakened. When the valve I54 is in the position shown inFigure 1 the suction eifect on the jet pipe I3I is fully effective andthe fuel to air mixture is therefore considered to be normal. Valve I54is adjusted to the normal or weak fuel-mixture setting by lever I01which is connected with arm I by links IIO, I09, I05 and I06 ashereinafter explained. When lever I01 assumes the position indicated atN valve I54 assumes the position for normal fuel-air mixture and when atW valve I54 assumes the position for weak fuel-air mixture.

Associated with the supercharger I23 is known form of control forautomatically regulating the The control is generally indicated by thereference numeral I33 and comprises a chamber I34, a capsule-stack I35mounted therein, a valve I36 carried by the stack of capsules, ahydraulic motor I31, the pressure fluid to which is regulated by thevalve I36 and a cam I38 which engages with a rod I39 secured to theupper end of the stack of capsules. The rod I39 is formed with a collar0 between which and the chamber I34 is placed a. compression spring "I.The chamber I34 communicates with the delivery side of the superchargerI23 by a pipe I42 so that the pressure of supercharge is communicated tothe stack of capsules I35. Accordingly with variations in the pressureof supercharge the stack of capsules I35 will expand or contract,thereby adjusting the valve I33 and permitting pressure fluid to pass tothe hydrauiic motor I31 so that the latter will adjust the valve I25through linkage I43, I44 and I48. Pressure fluid is delivered to valveI33 by pipe I45 and is capable of passing to by passages I41, theexhaust fluid being discharged from pipes I48.

The cam I38 and the throttle valve I25 are each simultaneously capableof adjustment by the throttle-lever l9.

The operation of the supercharger control described above is as follows:When the pilot adjusts the throttle-lever I9 to select a particularpower output from the internal-combustion engine, he simultaneouslyadjusts the cam I38 by linkage I50, and the throttle valve I throughlinkage I52, I53, I44, I45. When the throttlevalve I25 is thus adjustedthe quantity of combustion mixture which passes to the supercharger I23is varied and as a result the pressure of supercharge and the poweroutput of the internal-comfrom the motor bustion engine arecorrespondingly varied.

when the cam I38 is thus adjusted, rod I39, the capsule stack I andvalve I35 are moved axially as a unit so that valve I35 is opened.However, when the newly established pressure of supercharge istransmitted of capsules I35, valve I36 is readjusted and moved to theclosed position when the pressure of supercharge has the correct valueselected by adjustment of lever I9. The datum value of the superchargepressure is determined by the cam I38 which is adjusted by the pilot foreach power output selected. In the event that the pressure ofsupercharge departs from the value selected by the pilot, the automaticcontrol device is brought into operation as described to adjust thethrottlevalve I25 and reestablish the pressure of supercharge at theselected datum value.

Under certain circumstances it is desirable to obtain excess poweroutput from the engine and for this purpose there is provided a valvediagrammatically illustrated at 33 which is capable of placing thechamber I30 in communication with the atmosphere by a calibrated orificeI2. When this is done the pressure of supercharge within the chamber I38is reduced and as a result the stack of capsules I31 will expand,thereby moving the valve I33 to bring the motor I31 into operation toadjust the throttle-valve I25 and move it towards the open position. Thepressure of supercharge and the power output of the engine are thereforeincreased. The valves 33 and I54 are operated in a manner hereinafterdescribed.

The arms 98 and I09 which are respectively connected to valves 33 andI54 form a part of a mechanism which is shown more fully in Figure 2.There is associated with this mechanism a tank 8| having a supply ofantl-detonant which under certain circumstances is to be passed to thecarburetter I0 by a pipe 90 which communicates with the jet pipe |3| atII (Figure 1). The anti-detonant passes from the tank 8| by a pipe 82 toan electrically driven centrifugal pump 83 which is situated at a lowerlevel than the tank 8| so that if any liquid is present the pump issubmerged and generates a delivery pressure when operated but if noliquid is present no pressure is generated-even when the pump is set inoperation.

The electric motor I6 driving the pump 83 is supplied from a battery I5under the control of a master-switch 84 and a throttle-lever controlledswitch 85. This throttle-lever controlled switch may be so arranged thatit is closed when the lever I9 is moved beyond its normal working rangeto a maximum supercharge pressure position MP which is used only fortake off, all out the motor I31 by pipe I42 to the stack level speed orsome sucn special condition. It will be appreciated that the switch 85is not neces sarily mounted on may be connected to it or may becontrolled by any member which moves with the throttle: lever.

The delivery from the centrifugal pump 83 of the anti-detonant undersuitable pressure is taken by the pipe-connection 86 to a chamber 81from whence it passes by a metering-Jet 88, non-return ball-valve 89 andpipe-connection 90 to the inlet II connected with the fuel inlet I2 ofthe induction system of the engine.

From the chamber 81 a branch-pipe 9| admits the anti-detonant to achamber 92 having a flexible diaphragm 93 forming a wall thereof; thisdiaphragm may be loaded by a spring 94. The diaphragm is pivotallyconnected by a spindle 95 to an arm 96 on a rocking-shaft 91, and on theother end of this shaft there is secured an arm 98 which is connected bya link 98' to the rotatable valve 33 to open it when the shaft isrocked. The spindle of valve 33 is indicated at 99.

The shaft 91 also carries fast upon it an arm or shaft I00 whereon ismounted a bevel-planetpinion IOI which meshes with two bevel-gears orsegmental racks I02, I03, respectively, as shown in Figure 1. No claimis made to the construction of these racks per se as any well knownconstruction allowing the limited range of movement required wouldsufllce. For instance two bevel wheels facing one another and coupled bya bevel pinion |0I would answer the purpose. However, because of thelimited range of movement required complete bevel wheels are not usedand the segments I02 and I03 have been described as segmental racks. Thebevel-gear segment I02 is carried on a sleeve I04 which is free torotate on the shaft 91 and this sleeve carries a radial arm I05 which isconnected by a suitable linkage I06 with the pilot'sfuel-mixture-control-lever I 01. This lever as described above ismovable between two positions for normal miX- ture and weak mixture,respectively.

The bevel-gear segment I03 is carried on a sleeve I08 free to rotate onthe shaft 91 and carrying an arm I09 which is connected by a link 0 tothe fuel-mixture-control valve I54 at III.

Under normal conditions, when there is no demand for anti-detonant, thespring 96 acting on the diaphragm 93 maintains the shaft 91 in one ofits two limiting positions in which the bleed-valve 33 is closed. If thepilot operates his fuel-mixture-control-lever I01 it rocks the sleeveI04 through the linkage I09, and the gear segment I02 drives through theplanet-pinion IN the gear segment I03 to rock the sleeve I08. This driveis transmitted because the shaft I00 of the planet-pinion IN is heldstationary by the shaft 91. The movement of the sleeve I08 istransmitted to the mixture-control-valve I54 in accordance with thepilots requirements. When maximum supercharge pressure is required, thethrottle-lever is moved to its limiting position which closes the switch85 and starts the electric motor to drive the pump 83 so thatanti-detonant, if available from the tank 8|, is delivered underpressure to the chamber 81. Some of it passes thence through pipe 90 tothe inlet II to the induction system, and the pressure is also appliedto the diaphragm 93, the movement of which rocks the shaft 91 and opensvalve 33 by adjustment of rods 98 and 98'. Thefuel-mixture-control-lever I01 will ordinarily be in its normal" 75position N and is firmly held so that the bevelthe throttle-lever I9itself but an segment m is maintained stationary and the planet-pinionIll rolling on it transmits a drive to the bevel-gear segment I03. tatesthe sleeve llll and through the link Ill adjusts thefuel-mixture-control-valve I to the "weak mixture setting.

If there is no supply of anti-detonant available, no pressure isdelivered by the pump 83, or if during higher boost pressures during theoperation of the engine the supply of anti-detonant becomes exhausted,the pressure on the diaphragm 93 falls off and all the parts return totheir normal setting.

In the foregoing description reference has been made to anti-detonantsgenerally and for this purpose there may be used water, or a mixture ofwater and alcohol or a mixture of methanol and water, but it is to beunderstood that the invention is not restricted to the use of theseanti-detonants.

Weclaim! 1. In a supercharged internal-combustion engine, thecombination of manually-adjusted means controlling the power output ofthe engine, means operated by the adjustment thereof to a predeterminedsetting to effect a supply of antidetonant to the engine, means operatedby the pressure of the anti-detonant supply to eflect an increase in theboost-pressure beyond the normal value, means operable by the pilot toweaken the fuel-mixture, and means operable by the pressure of theanti-detonant supply to automatically weaken the fuel-mixture.

2. In a supercharged internal-combustion engiue, the combination of anautomatic boost-control device controlling the power-output of theengine, means for adjusting said boost-control device, means operable ona predetermined setting of the said adjusting means to override saidautomatic boost-controlling device, means operated by such setting toeflect a supply of antidetonant to the engine and means also operated bysaid setting to weaken the fuel-mixture.

3. In a supercharged internal-combustion englue, the combination ofmanually-adjustable means controlling the power output of the engine, achamber subjected to the boost-pressure of the engine, a flexiblecapsule in said chamber operatively connected with boost-controllingmeans, a bleed-valve from said boost-control-capsulechamber, means forsupplying anti-detonant under pressure to the engine, a flexiblediaphragm subjectedto the pressure of the anti-deton'ant, supply, arocking-shaft connected to said diaphragm to be rocked thereby, anoperative connection from said rocking-shaft to said bleedvalve, amanually-operable mixture-controllever, a mixture-control-valve,differential gearing connecting said lever and said valve, 9. connectionfrom said rocking-shaft to said gearing whereby movement of said shaftalso operates said mixture-control-valve.

t. In a supercharged internal-combustion englue, the combination of alever controlling the power output of the engine, an electric switchoperable at a predetermined setting of said lever, an electric motorcontrolled thereby, a pump driven by said motor to deliver anti-detonantto the engine, a chamber in communication with the delivery pipe of saidpump, a flexible diaphragm in said chamber, a connection from saiddiaphragm to a rocking-shaft, a radial arm on said rocking-shaft, abevel-pinion on said am, a first bevel-wheel engaged by said pinion, a

said sleeve to a manually-adjustable mixture-control-lever, a secondbevel-wheel engaged by said pinion, a sleeve on said second bevel-wheeloperatlvely connected to a mixture-control-valve, and an operativeconnection from said rocking-shaft to an automatic boost-control device.

5. In a supercharged internal-combustion engine, the combination withmeans operable on a predetermined setting of a lever controlling thepower output of the engine, to supply anti-deto nant under pressure tothe engine, a flexible diaphragm subjected to said pressure, aconnection from said diaphragm to a rocking-shaft, two sleeves rotatableon said shaft, a sun-wheel on each of said sleeves, a planet-wheelcarried by said rocking-shaft engaging said sun-wheels, an operativeconection from one sleeve to a mixturecontrol-valve, an operativeconnection from the other sleeve to a manually-operablemixture-control-lever, and an operative connection from saidrocking-shaft to an automatic boost-control device.

6. In a supercharged internal combustion engine, the combination ofmeans for controlling the power output of the engine, electric meansoperable at a predetermined setting of said first means, an electricmotor controlled thereby, a pump driven by said motor to deliveranti-detonant to the engine, a chamber in communication with thedelivery pipe of said pump, a flexible diaphragm in said chamber, aconnection from said diaphragm to a rocking shaft, a radial arm on saidrocking shaft, a bevel-pinion on said arm, a sleeve on said wheel. anoperative connection from said sleeve to a manually adjustable mixturecontrol lever, a second bevel wheel engaged by said pinion, a sleeve onsaid second bevel-wheel operatively connected to a mixture controlvalve, and an operative connection from said rocking shaft to anautomatic boost-control device.

'1. The method of preventing detonation in an internal combustion enginenormally supplied with power fuel such as gasoline delivered to theengine manifold under supercharger pressure, which comprises deliveringsupplementary antiknock fuel such as alcohol and water under con trol ofthe engine manifold pressure for mixture with the power fuel, duringsuch delivery of sup plementary fuel automatically reducing the deliveryof power fuel by a volume to be replaced by the supplementary fuel toproduce a mixture which will eliminate engine knocking during a periodof manifold pressure under which knocking would otherwise occur, andautomatically preventing such reduction in power fuel delivery in theevent of supplementary fuel flow failure.

8. A method of preventing detonation in an internal combustion enginewhich is supplied with a power fuel under supercharged pressure whichcomprises delivering supplementary antiknock fuel, such as alcohol andwater, at a predetermined engine manifold pressure for mixture with thepower fuel, during such delivery of the supplementary fuel automaticallyreducing the delivery of power fuel by a volume to be replaced by thesupplementary fuel, to produce a mixture which will eliminate engineknocking during a period of manifold pressure under which knocking wouldotherwise occur, and automatically preventing such reduction in powerfuel delivery in the event of supplementary fuel flow failure.

9. In a control system for an aircraft engine. adjustable meanseffective to limit the maximum quantity of air and fuel supplied to saidengine,

means for supplying a combustion modifying.

rate of flow of charging air, adjustable means to lo vary the ratio offuel to air in the fuel-air charge, means for adding a predeterminedamount of a combustion modifying ingredient-to said fuel-air charge, andmeans automatically efiective when said ingredient is added to changethe adjustment of both said air flow limiting means and said fuelairratio varying means.

11. In a water injection apparatus for a supercharged engine having anadjustable supercharger control device and an adjustable fuelair ratiocontrol device, means for feeding water to said engine, and meansoperatively associated with said water feeding means for adjusting atleast oneof said control devices.

DENIS HEATON THORNS. DUNCAN RAMSAY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,758,897 Evans May 13, 19302,002,483 Kimball May 21, 1935 is 2,221,405 Nallinger Nov. 12, 19402,252,415 Schwarz Aug. 12, 1941 2,295,656 Hersey et a1 Sept. 15, 1942FOREIGN PATENTS 20 Number Country Date 499,741 Great Britain 1939

